Splice joint lock

ABSTRACT

The invention relates to a lock for a splice joint used to releasably join two poles together end to end. The lock prevents the inadvertent withdrawal of the leaf spring finger from the superimposed holes of the splice joint. The lock comprises a ring rotatably positioned on one of the poles astride the leaf spring and having an inner surface comprised of a first, relatively large diameter segment which, when rotated into radial alignment with the leaf spring, permits withdrawal and a second, relatively smaller diameter segment which, when rotated into radial alignment with the leaf spring, frictionally engages and clamps the leaf spring to the pole and prevents withdrawal of the leaf spring finger.

BACKGROUND OF THE INVENTION

This invention relates generally to splice joints used to interconnectrelatively short lengths of pole together end to end to form a longerpole. These poles, with a wire raiser, cable lifter or similar accessoryattached to one end, are used by telephone and electric power utilities,contractors and CATV companies to perform maintenance on wires andtransmitting equipment atop utility poles. This same type of pole with apruning or saw head on one end is used by utilities and arborists totrim high limbs and branches from trees.

Since these poles frequently come into contact with wires carryingelectric current, the pole itself is manufactured of a nonconductivematerial such as wood or fiberglass. In order to facilitate storage andtransport of these poles from one place to another, they aremanufactured in relatively short lengths--for example 3 feet or 6feet--and then connected together when desired by a splice joint.

One type of splice used to connect pole sections together end to end isthe slip-joint splice. This type of joint generally comprisesinterlocking male and female portions secured to opposite ends of eachpole. When the male end portion is properly received in the female endportion, a through hole in a radial wall of one of the end portions issuperimposed with a through hole in the radial wall of the other. Anaxially extending leaf, or flat, spring is secured to the outer surfaceof one of the poles and has an inwardly extending finger, or button,which is positioned under spring tension in the superimposed holes. Inthis manner, each pole is prevented from moving either away from, ortwisting relative to, the other.

To disconnect the two poles, the finger is withdrawn from the alignedholes by moving the leaf spring away from the surface of the pole.

Because of the simple construction and light weight of the slip-jointsplice, it is one of the most common means of joining pole sectionstogether. Nevertheless, the slip-joint splice suffers from onesubstantial and long recognized disadvantage. Because the two polesections are held together solely by the leaf spring finger extendingthrough the superimposed holes, much of the tensile, compressive, andtwisting force exerted on the splice is absorbed by the finger. Heavyduty use of the poles causes the finger to "wallow" within thesuperimposed holes, gradually enlarging them. When in this condition,excessive tensile or twisting force on the splice can force the fingerfrom the holes, disconnecting the splice. For this reason, slip-jointsplices have traditionally been used only where they are not subjectedto excessive tensile or compressive loads. Other types of splices arecustomarily used under these heavy duty conditions and in general, areheavier, more expensive and difficult to connect and disconnect than theslip-joint splice.

So far as is known, no simple and inexpensive device has heretofore beendevised which can lock a slip-joint splice against inadvertentdisconnection, while being quickly and easily manipulated to permitdisconnection when desired.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a lock for asplice joint which is inexpensive and easy to use.

It is a further object of this invention to provide a lock for a splicejoint which can be quickly and easily manipulated solely by feel andwhile wearing heavy gloves.

It is still another object of this invention to provide a lock for asplice joint which enables the splice joint to be utilized under heavyload conditions, while safely maintaining the splice in its connectedposition.

These and other objects and advantages of the present invention areachieved in the preferred embodiment set forth below by providing a lockfor a splice joint of the type utilized for releasably joining two polestogether end to end. One of the poles has an end portion of a reduceddiameter for being matingly positioned in a tubular end portion of theother pole. Both poles have a through hole in a radial wall of theirrespective end portions for being positioned in superimposed relationwith each other. An axially extending leaf spring is secured to theouter surface of one of the poles and has an inwardly extending fingertoward the free end thereof for being positioned under spring tension inthe superimposed holes.

The lock itself comprises an arcuate clamp member rotatably positionedon one of the poles astride the leaf spring. The arcuate clamp memberhas an inner surface comprised of a first, relatively large diametersegment, which, when rotated into radial alignment with the leaf spring,permits withdrawal of the finger from the superimposed hole. The arcuateclamp member also comprises a second, relatively smaller diametersegment which, when rotated into radial alignment with the leaf spring,frictionally engages and clamps the leaf spring to the pole and preventswithdrawal of the finger from the superimposed holes. Preferably, thearcuate clamp member comprises a closed ring for encircling one of thepoles and the leaf spring positioned thereon, and includes grippingmeans positioned on its outer surface for aiding in its rotation byhand.

According to a preferred embodiment of the invention, the gripping meanscomprise two diametrically opposed, outwardly projecting ear-likemembers. Also, according to the preferred embodiment of the invention,the relatively large diameter segment of the arcuate clamp member isintegrally formed therein and has substantially the same radial width asthe leaf spring. The arcuate clamp member is adapted to slide freelyalong the longitudinal extent of the leaf spring when the relativelylarge diameter segment of its inner surface is radially aligned with theleaf spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the objects and advantages of the invention have been set forthabove. Other objects and advantages will appear as the description ofthe invention proceeds, when taken in conjunction with the followingdrawings, in which:

FIG. 1 is a perspective view of a preferred embodiment of the arcuateclamp member, comprising a ring, according to the present invention;

FIG. 2 is a perspective view of the male and female end portions,respectively, of a splice joint in disconnected position, and showingthe lock positioned astride the leaf spring on the female end portionand in retracted position;

FIG. 3 is a perspective view of a splice joint showing the male endportion matingly received in the female end portion and showing the ringin unlocked position astride the leaf spring;

FIG. 4 is a perspective view of the splice joint showing the joint ringin locked position;

FIG. 5 is a perspective view of the splice joint according to FIG. 4showing the ring unlocked and in retracted position.

FIG. 6 is a cross-sectional view of the splice joint taken substantiallyalong line 6--6 of FIG. 3; and,

FIG. 7 is a cross-sectional view taken substantially along line 7--7 ofFIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more specifically to the drawings, a splice joint lockaccording to a preferred embodiment of the invention is shown. As isshown in FIG. 2, two poles, 10 and 11, are in position to be releasablyjoined together end to end. Poles 10 and 11 are each comprised of anysuitable material, such as wood or fiberglass. Pole 10 has a male endportion 20 with a reduced diameter for being matingly positioned in afemale, tubular end portion 30 secured to the end of pole 11. Male endportion 20 is secured by means of a stud or rivet 21 to the end of pole10. As is also shown in FIG. 2, a through hole 22 is formed in anddefined by the radial walls of end portion 20.

The female end portion 30 is likewise secured to the end of pole 11 bymeans of a stud or rivet 31. A leaf spring 34 is secured by rivet 31 tothe female end portion 30 and extends axially along its outer surface.One end of the leaf spring 34 comprises a narrow tail 34a having acurved free end. This free end is positioned in a laterally extendingslot 35 and thereby substantially prevents the rotation of the leafspring 34 around a point defined by the rivet 31.

As is shown in FIG. 5, a through hole 36 is formed in and defined by thewalls of the female end portion 30. A downwardly extending finger 37 issecured to the underside of the leaf spring by means of a button headrivet 37a. The finger 37 is secured to the leaf spring 34 so as to benormally positioned in the through hole 36. As is also shown in FIG. 5,leaf spring 34 includes an integrally formed finger grip 38 which sitsin raised position above the surface of the female end potion 30 so thatit can be grasped between the thumb and forefinger and lifted, therebyremoving finger 37 from superimposed holes 36 and 22.

When the male end portion 20 is fully received within the female endportion 30, through holes 22 and 36 are axially aligned. By twistin themale and female end portions 20 and 30, respectively, relative to eachother radial alignment as well is achieved between holes 22 and 36. Whenthis alignment occurs, stud 37 under the urging of the leaf spring 34extends through and substantially beyond the aligned through holes 22and 36, thereby joining poles 10 and 11 together. To release the splicejoint, the stud 37 is withdrawn from the aligned through holes 22 and 36by grasping the finger grip 38 and pulling upwardly.

The general structure of the slip-joint splice, as described above, isold and well known in the art. Splice joints of this general type havebeen used in the power and utility industry for many years. However, asexplained above, the use of such splice joints has been avoided wherethe splices are potentially subjected to severe tensile or compressiveloads. Such loads have been known in the past to cause disconnection ofthe splice as a result of the forced ejection of the finger 37 from thesuperimposed holes 22 and 36.

Therefore, in accordance with the present invention locking means areprovided for preventing inadvertent withdrawal of the finger 37 from thesuperimposed holes 22 and 36. The locking means comprises an arcuateclamp member, preferably in the form of a closed ring shown at broadreference numeral 40, rotatably positioned on the female end portion 30of pole 11 astride the leaf spring 34. The ring 40 is preferably formedfrom a galvanized steel hose clamp manufactured by Oetiker, Inc. ofLivingston, N.J. For example, a ring 3/8" wide and having an internaldiameter of approximately 13/4" is suitable for use on a splice jointhaving an outside diameter of 11/2".

In its original form as a hose clamp, the ring 40 is provided with twodiametrically opposed, protruding segments. By use of a special tool,these segments are crimped together after placement of the hose clamp onthe hose, thereby reducing the diameter of the clamp sufficiently totightly encircle and grip the hose.

In accordance with the present invention, these segments are crimped andthereby form two diametrically opposed, outwardly projecting ear-likemembers 40a and 40b, and function as gripping means for aiding in handrotation of the ring 40 as shown in FIG. 1. Also integrally formed inthe ring 40 between the ear-like members 40a and 40b is a large diametersegment 40c. This large diameter segment 40c is formed by diestampingand serves as a guide to permit the ring 40 to freely slide along thelongitudinal extent of the leaf spring 34 when the large diametersegment 40c is in radial alignment therewith. The circumference of thering 40, with the exception of the relatively large diameter segment40c, defines a second, relatively smaller diameter segment 40d. The sizeof ring 40 may be adjusted by stretching on a punch press.

As is shown in FIG. 2, when the ring 40 is positioned astride the leafspring 34 adjacent the rivet 31, the two poles 10 and 11 may bereleasably joined together by inserting the male end portion 20 into thefemale end portion 30 while the finger 37 is held in withdrawn positionfrom hole 36. When holes 36 and 22 are aligned both radially andaxially, the leaf spring 34 is released and the finger 37 is thenpositioned in the superimposed holes 22 and 36. In order to lock thefinger 37 in the superimposed holes 22 and 36, ring 40 is positioned onthe leaf spring 34 intermediate finger grip 38 and the head 37a offinger 37. While in this position, ring 40 is twisted either clockwiseor counterclockwise (according to preference) thereby misaligning therelatively large diameter segment 40c and the leaf spring 34. Thismisalignment has the effect of reducing the diameter of the ring 40relative to the splice joint, thereby clamping the leaf spring 34 firmlyagainst the outer surface of the female end portion 30. As is best shownin FIG. 4, the raised head 37a of finger 37 prevents ring 40 from beingretracted while locked from its position directly adjacent the fingergrip 38.

The effect of this radial misalignment on the outside diameter of thefemale end portion end 30 relative to the inside diameter of the ring 40is illustrated and compared in FIGS. 6 and 7. As is shown in FIG. 6,when the relatively large diameter segment 40c is positioned in radialalignment with the leaf spring 34, a clearance of approximately 1/8"exists between the outer surface of female end portion 30 and the innersurface of ring 40. This clearance enables the ring 40 to easily slidealong the longitudinal extent of the leaf spring 34 and to clear theraised head 37a of the finger 37.

In contrast, FIG. 7 shows that when the ring 40 is rotated sufficientlyto radially misalign the relatively large diameter segment 40c and theleaf spring 34, this clearance no longer exists. As a result, the leafspring 34 is tightly clamped to the outer surface of the female endportion 30. This clamping effect effectively prevents inadvertentwithdrawal of the leaf spring finger 37 even under extreme tensile orcompressive forces.

Since ring 40, while in locked position, will not move over the raisedhead 37a of finger 37, sliding of the ring 40 along leaf spring 34 isprevented and the possibility of inadvertent withdrawal of finger 37eliminated. In addition, even if the large diameter segment 40c shouldbe inadvertently rotated back into alignment with the leaf spring 34,finger 37 is still locked within superimposed holes 22 and 36 so long asring 40 is not permitted to slide further than approximately one halfthe distance from finger grip 38 to rivet 31.

The ring 40 is prevented from sliding off the female end portion 30 bythe finger grip 38 on one end of the leaf spring 34 and on the oppositeend by a rivet with an enlarged heat (not shown) positioned on the outersurface of female end portion 30 in diametrical opposition to the rivet31.

To disconnect the splice joint, the ring 40 is twisted until the largediameter segment is realigned with the leaf spring 34. The ring 40 isthen free to slide back to rivet 31. With ring 40 thus retracted, theleaf spring 34 may be grasped at the finger grip 38 and pulled away fromthe surface of the female end portion 30, removing finger 37 fromaligned through holes 36 and 22. This step is illustrated in FIG. 5.

Described above is a preferred embodiment of a lock for a splice jointwhich is inexpensive, easy to operate and maintenance-free. Variousdetails of the invention as described above may be changed withoutdeparting from the scope of the invention. Furthermore, the foregoingdescription is for the purpose of illustration only and not for thepurpose of limitation--the invention being defined by the claims.

We claim:
 1. In a splice joint for releasably joining two poles togetherend to end, one of the poles having an end portion of a reduced diameterfor being matingly positioned in a tubular end portion of the otherpole, both poles having a through hole in a radial wall of theirrespective end portions for being positioned in superimposed relationwith each other, and an axially extending leaf spring secured to theouter surface of the end portion of one of the poles and having aninwardly extending finger toward the free end thereof for beingpositioned under spring tension in the superimposed holes; thecombination therewith of locking means for preventing inadvertentwithdrawal of the finger from the superimposed holes, and comprising anarcuate clamp member rotatably positioned on one of the poles astridethe leaf spring and having an inner surface comprised of a first,relatively large diameter segment which, when rotated into radialalignment with the leaf spring, permits withdrawal of the finger fromthe superimposed holes, and a second, relatively smaller diametersegment which, when rotated into radial alignment with the leaf spring,frictionally engages and clamps the leaf spring to the pole and preventswithdrawal of the finger from the superimposed holes, said clamp memberadapted to freely slide along the longitudinal extent of the leaf springwhen said relatively large diameter segment of the inner surface thereofis radially aligned with the leaf spring, and wherein said ring isadapted to frictionally engage and clamp the leaf spring to the pole ata point between the finger and the free end of the leaf spring.
 2. In asplice joint according to claim 1, wherein said arcuate clamp membercomprises a closed ring encircling one of the poles and the leaf springpositioned thereon.
 3. In a splice joint according to claim 2, whereinsaid ring includes gripping means positioned on its outer surface foraiding in the hand rotation thereof.
 4. In a splice joint according toclaim 3, wherein said gripping means comprises at least one outwardlyprojecting ear-like member.
 5. In a splice joint for releasably joiningtwo poles together end to end, one of the poles having an end portion ofa reduced diameter for being matingly positioned in a tubular endportion of the other pole, both poles having a through hole in a radialwall of their respective end portions for being positioned insuperimposed relation with each other, and an axially extending leafspring secured to the outer surface of the end portion of one of thepoles and having an inwardly extending finger toward the free endthereof for being positioned under spring tension in the superimposedholes, the combination therewith of locking means for preventinginadvertent withdrawal of the finger from the superimposed holes, andcomprising a closed ring rotatably positioned on and encircling one ofthe poles astride the leaf spring positioned thereon, and having aninner surface comprised of a first, relatively large diameter segment,which when rotated into radial alignment with the leaf spring, permitswithdrawal of the finger from the superimposed holes, a secondrelatively smaller diameter segment, which, when rotated into radialalignment with the leaf spring, frictionally engages and clamps the leafspring to the pole and prevents withdrawal of the finger from thesuperimposed holes, said ring being adopted to freely slide along thelongitudinal extent of the leaf spring when the relatively largediameter segment of the inner surface thereof is radially aligned withsaid leaf spring, and gripping means positioned on the outer surface ofsaid ring for aiding in the hand rotation thereof, and wherein said ringis adapted to frictionally engage and clamp the leaf spring to the poleat a point between the finger and the free end of the leaf spring.
 6. Ina splice joint according to claim 5, wherein said gripping meanscomprises two diametrically opposed, outwardly projecting ear-likemembers.
 7. In a splice joint according to claim 5, wherein said first,relatively large diameter segment of said ring is integrally formedtherein and has substantially the same diametrical width as the leafspring.
 8. A lock for a splice joint of the type utilized for releasablyjoining two poles together end to end, one of the poles having an endportion of a reduced diameter for being matingly positioned in a tubularend portion of the other pole, both poles having a through hole in aradial wall of their respective end portions for being positioned insuperimposed relation with each other, and an axially extending leafspring secured to the outer surface of one of the poles and having aninwardly extending finger toward the free end thereof for beingpositioned under spring tension in the superimposed holes, said lockcomprising:a. An arcuate clamp member for being rotatably positioned onone of the poles astride the leaf spring; b. said clamp member having aninner surface comprised of a first, relatively large diameter segment,which, when rotated into radial alignment with the leaf spring isadapted to freely slide along the longitudinal extent of the leaf springaway from said inwardly extending finger in order to permit withdrawalof the finger from the superimposed holes; and c. A second, relativelysmaller diameter segment which, when rotated into radial alignment withthe leaf spring, frictionally engages and clamps the leaf spring to thepole and prevents withdrawal of the finger from the superimposed holes,and wherein said leaf spring is adapted to frictionally engage and clampthe leaf spring to the pole at a point between the finger and the freeend of the leaf spring.
 9. A lock for a splice joint according to claim8, wherein said first, relatively large diameter segment of said arcuateclamp member is integrally formed therein and has substantially the samediametrical width as the leaf spring.
 10. A lock for a splice jointaccording to claim 8, wherein said arcuate clamp member comprises aclosed ring for encircling one of the poles and the leaf springpositioned thereon.
 11. A lock for a splice joint according to claim 10,wherein said ring includes gripping means positioned on its outersurface for aiding in the hand rotation thereof.
 12. A lock for a splicejoint according to claim 11, wherein said gripping means comprises atleast one outwardly projecting ear-like member.
 13. A lock for a splicejoint according to claim 11, wherein said gripping means comprises twodiametrically opposed, outwardly projecting ear-like members.